ABSTRACT
In this study, the interplay among the phospholipid 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) as a model membrane, the nonsteroidal anti-inflammatory drug naproxen, and the saponin ß-aescin are investigated. The naproxen amount was fixed to 10 mol%, and the saponin amount varies from 0.0 to 1.0 mol%. Both substances are common ingredients in pharmaceutics; therefore, it is important to obtain deeper knowledge of their impact on lipid membranes. The size and properties of the DMPC model membrane upon naproxen and aescin addition were characterized with differential scanning calorimetry (DSC), small- and wide-angle X-ray scattering (SAXS, WAXS), and photon correlation spectroscopy (PCS) in a temperature-dependent study. The interaction of all substances was dependent on the lipid phase state, which itself depends on the lipid's main phase transition temperature Tm. The incorporation of naproxen and aescin distorted the lipid membrane structure and lowers Tm. Below Tm, the DMPC-naproxen-aescin mixtures showed a vesicle structure, and the insertion of naproxen and aescin influenced neither the lipid chain-chain correlation distance nor the membrane thickness. Above Tm, the insertion of both molecules instead induced the formation of correlated bilayers and a decrease in the chain-chain correlation distance. The presented data clearly confirm the interaction of naproxen and aescin with DMPC model membranes. Moreover, the incorporation of both additives into the model membranes is evidenced.
ABSTRACT
BACKGROUND/AIM: Most colorectal carcinomas develop from an adenoma-carcinoma sequence to metastatic disease. The aim of the present study was to use lectins, carbohydrate-binding proteins, to detect changes in glycosylation during this malignant progression. MATERIALS AND METHODS: Sections from normal colorectal mucosa, high-grade intraepithelial neoplasia, submucosal colorectal carcinoma and metastases from patients who underwent colorectal surgery were stained by lectins with different sugar specificities namely agglutins from Wheatgerm (WGA), Helix pomatia (HPA), Phaseolus vulgaris (PHA-L), Ulex europaeus (UEA-I), Sambucus nigra (SNA-I), Canavalia ensiformis (Con A), Galanthus nivalis (GNA) and Dolichos biflorus (DBA). RESULTS: Binding patterns of all lectins except SNA-I, Con A and DBA changed during the adenoma-carcinoma sequence. CONCLUSION: The results indicate that lectins specific for mannose, N-acetylgalactosamine, N-acetylglucosamine, sialic acid, ß-1,6-branched oligosaccharides and α-1-fucose may be associated with malignant progression.
